Hallow Dear,
I believe when you state 4 weeks of
pregnancy, it is 4 weeks after you have missed your period.
Yes, such a heavy bleeding associated with severe cramps in abdomen is most likely to be due to abortion. Usually, when there is bleeding associated with pain in lower abdomen, such pregnancies cannot be salvaged. If you have noticed any white 'clot' on your pads, the abortion is confirmed.
However, I would advice you to undergo
ultrasonography. If the products of gestation are seen in the
uterine cavity, it means the baby (may be completely or partially) is still present in the uterine cavity. If there are no heart beats seen in scan, then it is
incomplete abortion and you need to get it completed by evacuation of the uterine cavity. If no products are seen in the uterine cavity, it means you have aborted completely and no further intervention is required.
Pregnancy test on urine will not be conclusive since these tests become negative only after more than a week after the baby has become nonviable.
Please report to your Gynaecologist ASAP to have earliest intervention before you loose substantial blood.
I hope this has guided you for your immediate action.
Dr. Nishikant Shrotri